Scientific Models: Practical Uses of 3D Printing in Science Classes

Craig is a Sr. Chemistry and Physics Teacher at WL Seaton Secondary in Vernon BC. He actively looks for ways to incorporate technology into his practice.@craigihoward

Science classes have always been enhanced by the use of physical models to help students visualize and understand abstract concepts or phenomena that are normally outside the scope of direct observation by their senses. Some of these models are ubiquitous and easy to obtain, while others are too specialized to justify the cost of purchasing for a few minutes use in a single lesson. 3D printing is changing the economics of using physical models for briefly discussed topics.

Models make the abstract real

High school science classes expose students to events, phenomena and concepts that lie outside of their daily experience. The ability to see and interact with 3D models provides deeper understanding of the phenomena. Students can safely interact with models to understand structures, see how different parts interact with each other and make and test predictions about how real life objects will behave. Some models, because they are used throughout entire units, in several courses, or are so valuable to the understanding of a concept, are common supplies in most science departments. Teachers often work with molecular model kits, model hearts, model cells and bohr models of atoms.

Model Limitations

In spite of the obvious benefits of using models to help teach students, supply catalogues are full of useful models that don’t get purchased and used because the cost/benefit analysis doesn’t make them worthwhile. These models sometimes cost hundred of dollars and are only really useful for demonstrating single phenomena in individual classes. As budgetary responsibility always needs to be considered, these specialized models usually aren’t purchased and students aren’t provided opportunities to work with them.

3D Printing

Over the past few years, 3D printing has moved from being limited to professional engineering and prototyping settings that could afford the tens of thousands of dollars costs associated with the printers, to being common among hobbyists and easily affordable to a school or school district. Inexpensive, small printers can be purchased for a couple hundred dollars and prosumer level machines are available for well under $1000.

Our science department purchased the popular and well reviewed Creality CR-10S printer along with some accessories and a significant supply of consumables this spring for under $1500. So far, the experience with the printer has been positive. 3D printers are a little finicky to work with and new users need to be prepared to do some troubleshooting and fine tuning to get useable models. But once the print is dialled in, the resulting 3D plastic objects can be just as detailed and robust as mass produced injection moulded products.

A typical print of a model large enough to be seen across a classroom and robust enough for student handling will require 8-24 hours to produce. This is much too slow for an entire class to print their own projects, but is much faster than ordering a demonstration model from a catalogue and waiting for it to be shipped to the school. Since purchasing the printer, it has been running most days and slowly building up our supplies of models. It doesn’t matter if the model is only needed for 10 minutes to supplement one Chemistry 11 lesson, it is still financially worthwhile to print the object. The cost in plastic is often less than a quarter per model, compared to tens or hundreds of dollars for ordered models.

Finding models to print

One of the wonders of the modern world is the ready access we have to information. Most of the models that a science teacher would want to print have already been designed and shared by others. A convenient source of free models is www.thingiverse.com The models of the s, p, d, and f orbitals shown above were found here https://www.thingiverse.com/thing:1194700

If one is truly ambitious, or in need of such a specialized model that it hasn’t yet been shared online, any CAD program can be used to design objects to be printed. Regardless of the source of the model, specialized software called a slicer needs to analyze the model to write instructions for the printer to follow to print the object. Fortunately for budget conscious districts and departments, there are several free and effective slicers available. The program we have used with positive results is Cura https://ultimaker.com/en/products/ultimaker-cura-software

Conclusion

At the early stages of experimenting with 3D printing educational models, the process is producing high quality teaching aids at minimal cost per item. This looks to have been a good choice for our science department and it might be a good choice for yours too.